Earth boring drill



Oct. 27, 1936. c D 2,058,625

EARTH BORING DRILL Filed March 22, 1934 Mme, e

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ATTORNEY Patented Oct. 27, 1936 UNITED STATES PATENT OFFICE EARTH BORING DRILL Clarence E. Reed, Wichita, Kans., assiznor to Chicago Pneumatic Tool Company, New York, N. Y a corporation of New Jersey Application March 22, 1934, Serial No. 716,879

23 Claims. (Cl. 255-71) This invention relates to rotary earth boring which bottom wall is virtually the exterior vertical drills of the type carrying a plurality of rotary wall of the bit head. toothed cutters for disintegrating the formations The laterally open recess in which the shank 3 at the bottom of the hole. The cutter organizalies is formed between walls to which extend out- 5 tion includes side cutters spaced about the drill wardly and downwardly from the side of the main 120 degrees apart and of frusto-conical shape with body of the bit head, the lower ends of these walls independent cylindrical cutters disintegrating the reaching down below the lower face of said bit area usually traversed by the apex portions of head. The spindles are not supported at their frustoconical cutters. free ends, but are enclosed by the wall of the It is an object of the invention to provide a cutters. The cutter with its spindle and base 10 drill having frustoconical side cutters of difierplate I and shank 3 are insertable into place as ent altitudes and cylindrical cutters for disinone unit. The flange l bears on the lower integrating the portion of the bore hole usually clined edges 41) of the wall portions 4a.. One of traversed by the apex portions of the frustoconithe spindles is indicated in dotted lines at la cal cutters Several dv s sult, among within the cutter of greatest altitude. The pairs 15 which are: much open space about the individual of walls to projecting laterally from the side of cutters is provided so that the disintegrated forthe main body of the bit head provide in effect mation can freely pass from under the drill; a supporting arms extending laterally and downbetter proportioning of the teeth sizes to the work wardly from the bit head with ample vacant 110 be done is possible then y us g t ap spaces between said arms for the upflow of the portions of cones traversing the same area; a flushing fluid and cuttings from the bottom of the more rapid Penetration e ul f om the e mi hole. The recesses between the walls 4a. in which tion of the dragging efi t 0 t e sma hs e the shanks 3 of the roller cutter spindles lie as toothed apex portions of the usual forms of frustoabove stated are openlaterally and also downconical cutters; a substantially flat bottomed hole wardly. The shanks 3 lie exposed laterally in can be produced; the frustoconical cutters indithese recesses and may be readily welded remote vidually may be constructed of low altitudes and from the bearing surfaces of the spindles.

of different altitudes in the same bit, resulting in Th cylindrical cutters Ila. are mounted in a.

a regulated and Controlled pp e 0f the teeth 'hanger I4 which has a portion Mb fitting up into thereon when it is desired to use frustoconical the bore 410 of the bit head. The hanger in 1'91 cutters whose projected apices do not lie in the spect to the portion thereof in which the cutters longitudinal axis of the bit, but preferably lie Ma are mounted is offset from the vertical axis across the axis from the body of the cutter. of the drill. There is a shoulder at Mo on the Another object is to provide hangers or supports hanger which abuts the lower edge of the wall individual to the cuttgs, which hangers are of the bit head and there is a welded connection 35 mounted in laterally open recesses at the exterior at Md between this shoulder and the bit head of the bit head. wall. The portion Nb of the hanger is provided In the drawing: with ports He and If for delivering flushing Figure 1 is a vertical sectional view of the fluid to the cutters.

drill, this section being taken in a plane through The walls to provide between their lower ends 40 the axis of the largest of the side cutters and ,a space or notch opening downwardly and also through the axis of the cylindrical cutters. open laterally both inwardly towards the vertical Fig. 2 is a side elevation of the drill looking axis of the drill as well as outwardly. The upper towards the end of the axis of the cylindrical end of the notch may be said to be defined by the cutters. wall or shoulder 40, Fig. 1. This shoulder pro- 45 Fig. 3 is abottom plan view. vides a bearing surface positioned on the body The construction of the cutter hanger or supportion of the bit head and extending from each porting means is of the unit type, in which the laterally open recess at the outer side of said cutter is assembled on a spindle integral with a body portion to the cutter receiving space at the base flange l, a spindle support or body portion 2, under face of said body portion. The web or body 50 and an upwardly projecting stem or shank 3. portion 2 of the hanger unit has substantially flat This hanger is inserted into an exterior laterally sides fitting the opposing inner faces of the walls open recess formed in. a portion of a bit head 4', 4a where these walls reach below the lower end of and welded as indicated at '5, said stem'bearing the body'of the bit head. This body portion of on the bottom wall of said exterior" reces'sfand the hanger presents. a. shoulder 4d bearing against a this wall 40 which therefore provides a construction for taking the upthrust of the cutter imparted through the hanger, and this shoulder is substantially as wide as the thickness of the wall of the body of the bit head.

In the drawing all the cutters are indicated as having teeth with a flat crest 6 instead of the usual sharp edge. This invention provides means for regulating the amount of the sidewise movement per cutter and the invention distributes the total of the sidewise movement of the contacting edges over a sufficient number of individual cutters whose dimensions and relative positions in the assembly can be arranged securing best results of a balanced action resulting in speed and efliciency of operations.

The frustoconical cutter of the greatest altitude is shown in Figs. 1 and 3 at the left thereof, at 6a-6b. This cutter is arranged with its upwardly and outwardly inclined axis in the same vertical plane with the axis of the cylindrical cutters Ma.

The frustoconical cutters of lesser altitude are shown at 9 and I U, the cutter l0 being of less altitude than the cutter 9, and each of these outters travels about the vertical axis of the drill. The projected apex of each frustoconical cutter lies preferably on the side of the vertical axis of the drill opposite to that upon which the main body of the cutter is located. Each of the frustoconical cutters 9 and I0 has associated therewith a toothed cutting zone indicated at I I which is so related to the organization that it cuts an annular area at the bottom of the hole inclining upwardly and outwardly adjacent'the side wall of the hole and constitutes a side roller cutter which tracks the other side roller cutters l I.-

The included angle of a vertical section along the axis of each frusto-conical cutter, that is the angle which includes the projected apex and the opposite side lines of the cutter diverging therefrom, is substantially less than a right angle, and the inclination upwardly and outwardly of the axes of the frustoconical cutters is such that a substantially flat bottom hole will be formed. The character of the included angle just mentioned and the angle of inclination of the cutter axis is such as will facilitate the action of the flushing fluid in keeping the cutters free from accumulated material, and by reason of the large spaces between the cutters at the center of the drill, the disintegrated material will be freely discharged from beneath the drill, thus providing for the maximum unimpeded action of the cutters upon the uncut formation at the bottom of the hole.

By reason of the flat surfaces 6 on the teeth instead of sharp edges the teeth act as punches in penetrating the formation, and while in the formation the teeth are given a lateral twisting action, causing a breaking up of the adjacent formation.

This action also causes the flat surfaces at the free edge portions of the teeth to receive a grinding action from the' material acted on which preserves the flat formation along the ends of the teeth.

It will be noticed from Fig. 3 that the cutter of greatest altitude is'made up of the portion 6a acting as a side cutter to cut an annular area at the side wall of the hole and beyond the projected side of the bit head structure, and it is made up also of the'frustoconical portion 6b which cuts an area inwardly of the bottom of the hole reaching inwardly towards the vertical axis of the drill.

Further it will be noticed that the cylindrical cutter means, desirably made up of the two outters Ma, are mounted close to the vertical axis of the drill, but on the opposite side of said vertical axis from where the cutter of greatest altitude 6a-6b is located. This cylindrical cutter means is on an axis perpendicular to the vertical axis of the drill. It cuts an annular area close to the said vertical axis and together with the cutters 6a--6b it cuts substantially the entire area at the bottom of the hole including the clearance beyond the drill head. Any small portion left uncut between the paths of the cutters Ila-6b and Ma is negligible. All of the cutter means (la-6b and a have their axes located in the same diametrically vertical plane passing through the vertical axis of the drill. As viewed in bottom plan view Fig. 3 the cutter 6a6b and the other two side cutters there shown are spaced with their axes in diametrical planes substantially apart from each other. The vertical plane in which the axes of the cylindrical cutters and the cutter GaP-Bb lie passes about midway between the other two side cutters, both of which, so far as their substantially cylindrical peripheral portions are concerned, track the cylindrical toothed portion 6a of the cutter 6a--6b and they all cut clearance at the side of the bore hole beyond the bit head structure. A well balanced organization is thus provided, the weight of the cutter 6a--6b of greatest altitude being balanced more or less by the cylindrical cutter means Ida and the support therefor on the opposite side of the vertical axis of the drill. The cutters a with their support and the inner end of the cutter of greatest altitude lie in the space between the other two side cutters which, as appears from Fig. 3 diverge from each other leftward. The hanger shanks are substantially rectangular in cross section.

I claim:

1. A roller bit comprising a bit head three frustoconical side cutters of different altitudes spaced at 120 apart about the bit head and independently rotatable cylindrical cutter means therebetween, said cylindrical cutter means having its axis in the same vertical plane passing through the vertical axis of the drill as the axis of the frustc-conical cutter of greatest altitude and on the opposite side of the verticalaxis of the drill from the said greatest altitude frustoconical cutter.

2. In a rotary earth boring drill, the combination of side cutters of frusto-conical form and of different altitudes having their cutting teeth of different lengths, said frusto-conical cutters each having a toothed base zone angularly disposed relative thereto, and substantially tracking each other, and independently rotatable non-true rolling cutters adjacent the vertical axis of the drill disintegrating the area at the bottom of the hole between the drill axis and the paths cut by the said frusto-conical cutters of different altitude, substantially as described.

3. In combination in an earth boring drill, a bit head, cylindrical cutter means arranged on a substantially horizontal axis near the vertical axis of the drill to cut an annular path about the same, aside roller cutter of frustoconical form whose axis inclines upwardly and outwardly in the same vertical plane with the axis of the cylindrical cutter means, said cutter being of com- 75 paratively great altitude, and other side roller cutters of frustoconical form of lesser altitude and on opposite sides of the vertical plane in which the axis of the cylindrical cutter means lies, said other side cutters being on outwardly and upwardly inclined axes, substantially as described.

4. An earth boring drill comprising a bit head, three side roller cutter members spaced apart at 120 with their axes inclining downwardly and inwardly towards the vertical axis of the drill and lying in difierent diametrical planes, each member having a toothed periphery tracking the toothed peripheries of the other cutter members and cutting an annular path adjacent the side wall of the hole, one of said toothed side roller cutter members having associated therewith a toothed frusto-conical portion extending with its apex portion to near the vertical axis of the drill, and other cutter means across said vertical axis of the drill from the said frusto-conical portion and cutting an annular area adjacent the vertical axis of the drill, said last mentioned cutter means together with the side roller cutter member and its associated frusto-conical portion cutting the entire area at the bottom of the hole, substantially as described.

5. An earth boring drill comprising a bit head having on its outer side spaced apart pairs of substantially parallel walls extending in vertical planes and projecting below the lower edge of the body of said bit head, the inner edges of said pairs of walls being inclined downwardly and out wardly and having between them at their point of junction with the body of the head a shoulder facing downwardly, a hanger for a rotary toothed cutter comprising a spindle inclining downwardly and inwardly and free at its inner end, a body .portion with which said spindle is integral, seated between the lower projecting ends oi said parallel walls and against said shoulder, and an upwardly extending stem portion lying between said parallel walls on the outer side of ,the head and secured in place therebetween, said stem portion being integral with said body portion and a roller cutter mounted on said spindle, substantially as described.

6. An earth boring drill comprising a bit head, side roller cutters disposed at 120 apart about the bit head, tracking each other and cutting an annular path adjacent the side wall of the hole, non-tracking cutter means cutting an area at the bottom of the hole between the path cut by the side cutters and the vertical axis of the drill, and a hanger individual to each of the side roller cutters, said bit head having laterally and downwardly open recesses in its exterior, said hangers having shank portions located in said recesses and welded to the walls thereof, substantially as described, each hanger having -a spindle for 4 mounting the corresponding frusto-conical cutter.

7. A bearing for supporting a roller cutter of an earth boring drill comprising a body portion to fit into a notch in the lower edge oi a bit head, and having an integral flange inclining upwardly and laterally to fit against a corresponding surface within the bit head, an integral spindle extending from said body portion, and an integral shank extending up from said bodyportion at a point at the extreme outer portion of said body, and at an angle to the axis of the spindle.

8. In an earth boring tool a bit head having a centrally disposed flushing fluid bore therethrough, a roller cutter having a trusto-conical apex zone and an anguiarly disposed base zone, said cutter being disposed at the side of the bit head, and said base zone cutting a path including clearance for the bit head, a downwardly and inwardly inclined spindle upon which thecutter is rotatably mounted, means attaching the portion of the spindle at the base zone of the cutter to the bit head, and a removable closure member in the bore of the bit head independently of the cutter attaching means and having a flushing fluid port therethrough directing fluid directly upon the base zone of the cutter.

9. In an earth boring tool a bit head having a centrally disposed flushing fluid bore therethrough, a roller cutter having a frusto-conical apex zone and an angularly disposed base zone, said cutter being disposed at the side of the bit head, and said base zone cutting a path including clearance for thebit head, a downwardly and inwardly inclined spindle upon which the cutter is rotatably mounted, means attaching the portion of the spindle at the base zone of the cutter to the bit head, and a removable cutter carrier independent of the side cutter attaching means having an upper portion disposed in the bore of the bit head, and a lower portion having means for mounting a center roller cutter, the upper portion of said carrier serving as a closure member for the bore of the bit head and having a flushing fluid port therethrough directing fluid directly upon the base zone of the side cutter.

10. A roller boring drill comprising a head, a

cutter recess in the lower end of said head, a plurality of cutter units mounted for rotation and cutting in non-tracking paths over the central area of the bottom of the bore hole, and other cutter units including side cutter elements track ing each other over an annular area adjacent to the side of the bore hole and with their axes in ciined downwardly and inwardly, each element having a frustoconical portion projecting inwardly from the tracking portion thereof, which tracking portion is angularly disposed relative to the frusto-conical portion, each cutter unit being secured to the bit head independently and exteriorly thereof by a hanger member supporting a spindle of the cutter unit.

11. In an earth boring tool, a bit head, a frusto-conical cutter cutting an area at the side of the hole including clearance for the bit head, a downwardly and inwardly inclined spindle mounting said cutter, means for supporting the outer end of the spindle from the bit head leaving the inner end free, a carrier attached at its upper portion to the bit head independent of the frustoconical cutter supporting means, cylindrical roller cutter means carried by the lower portion of the carrier and on the opposite side of the bit head axis from the frusto-conical cutter means, said roller cutter means rotating on an axis perpendicular to the bit head axis and lying in the vertical plane in which the axis of said spindle lies, said roller. cutter means cutting the area uncut by said frusto-conical cutter, and other roller cutter means adjacent said center cutting means and cutting an area at the side of the hole.

12. A bit head comprising a hollow cylindrical body portion interiorly screw threaded at one end and having means comprising recesses defined by wall portions spaced at 120 degrees about the lower end of the body portion, a frustoconical roller cutter unit for each of the said recesses having a supporting element located in the recess individual thereto, each of the side cutters having a base zone and an apex zone inclined thereto and a removable member having a fluid conduit directing fluid to impinge on the base cutting zone of said roller cutter, said conduit being positioned for washing both cutting zones. I

13. An earth boring drill comprising a bit head having a downwardly extending side wall portion with its inner face inclined downwardly and outwardly, said wall portion having a downwardly open notch defined at its upper end by a cross wall from the outer edge of which a wall of the bit head extends upwardly at an angle thereto and forms the bottom wall of an exterior recess laterally open and communicating with said notch, and defined by substantially parallel spaced apart walls extending outwardly in respect to the bit head, a roller cutter, a support therefor consisting of a spindle, the free end of which is enclosed by said roller cutter, a body portion fitting in the notch and having a flange bearing upon the inclined inner face of the side wall portion of the bit head, a shoulder engaging the upper cross wall of the notch and a stem extending upwardly from the outer end of the shoulder at an angle to the spindle and lying against the bottom wall of the recess, said stem being welded to the wall of the recess, said spindle, flange body portion and upwardly and angularly extending stem being formed in one piece, substantially as described.

14. In an earth boring bit, a bit head having a recess at its lower end, one side of which is defined by the inside wall of a depending portion on the bit head, said inside wall being inclined to diverge downwardly and outwardly with respect to the bit axis, the outside wall of said depending portion having a recess extending upwardly between portions of and opening exteriorly of the bit head, a spindle support having an upper extension received within the exterior recess and having a flange engaging the inclined inside wall, and a spindle carried by the support and projecting downwardly and inwardly from the support and extending at right angles to the flange, said spindle being adapted to support a roller cutter.

15. A bearing member for supporting a cutter at the side of an earth boring tool, having a stem portion for attachment by weldingto the exterior of a bit head above and remote from the spindle and bearings of a roller cutter, a surface on said member extending laterally from the stem to provide a bearing against abit head to take upward thrusts, and a flange at the lower part thereof disposed at an angle to the direction of length of the stem portion and providing inclin'ed thrust surfaces on its opposite sides, said bearing surface presenting a shoulder located between the flange and the stem.

16. A bearing for a roller cutter of an earth boring drill comprising a body portion adapted to flt parallel walls of a notch of the bit head and seat on the ceiling of said notch, said bearing having a flange projecting from said body portion at its inner portion and a shank extending up from said body portion at the extreme opposite side thereof from where said flange is 10- caled, thus adapting said shank to be secured to the outer side face of the drill head remote from said body portion and with the flange resting against the inner side of the bit head wall, and

a spindle for mounting the roller cutter projectto flt in a downwardly open notch of a bit head, said body portion having its outer face extending in a vertical plane substantially parallel with the vertical axis of the drill, and its inner face at an upwardly and inward inclination relative to said axis, with a flange extending from said inclined face, a spindle for mounting a roller cutter, projecting downwardly and inwardly towards the vertical axis of the drill from the inner side of said body portion, and a shank integral with the body portion extending upwardly therefrom with its lateral face forming substantially a continuation of the outer vertical face'of the body portion, for attachment to the exterior of the bit head, said lateral face of shank being exposed at the side of the bit head to take wear, substantially as described.

18. A roller boring drill comprising a bit head having at its lower end a downwardly open re-- cess, said recess being situated between depending walls formed on the bit head, one wall having an inside surface diverging downwardly with re-* spect to the bit head axis, the lower extremity of said wall having a downwardly open notch, the ceiling of which is defined by a shoulder on said head, and a removable bearing member having a body portion seated in said notch in engagement with the side walls thereof and said shoulder, the bearing having a shank extending upwardly, and being seated in an outwardly open recess formed in the outside surface of the head, a portion of said bearing member projecting inwardly into the bit head recess, and having a flange situated within the bit head recess and bearing against the inside surface of the depending wall to sustain the bearing] member against thrusts outwardly from the bit head axis.

19. A roller boring drill comprising a bit head having at its lower end a downwardly open recess, said recess being situated between depending walls formed on the bit head, one wall having an inside surface diverging downwardly with respect to the bit head axis, the lower extremity of said wall having a downwardly open notch, the upper end of which is deflned by a shoulder on said wall, and a removable bearing member havmg a body portion seated in said notch in engagement with said shoulder and having a shank extending upwardly, said shank being seated in an outwardly open recess formed on the outside surface of the wall, a portion of said bearing member projecting inwardly into the bit head recess, the bearing member having a flange situated within the bit head recess and bearing against the inside surface of the depending wall to sustain the bearing member against thrusts outwardly from the bit head axis, said flange, body portion and shank being integral with each other.

20. A bearing member adapted to support a cutter at the side of an earth boring tool in an inclined position to cut clearance for the bit head of said tool, said bearing member having a stem portion for attachment to the exterior of the bit head and adapted to be welded to the head in a locality remote from the bearing surfaces of the cutter, a flange on the lower part of the bearing member disposed at an angle to the direction of length of the stem portion and providing inclined thrust surfaces on its opposite sides, and a spindle projecting perpendicularly from one of the thrust surfaces of the flange to mount a roller cutter, said flange at its lower end terminating substantially in line with the outer face of said stem.

21. An earth boring drill comprising two rotary toothed cutting means disposed with their axes in different vertical planes intersecting the vertical axis of the drill, for cutting an annular area at the side of the bottom of the hole and clearance beyond the side of the drill, a third rotary cutting means, disposed axially in a vertical plane spaced apart 120 from the planes first mentioned, said third cutting means having a base portion substantially tracking the two rotary cutting means first mentioned and also having frusto-conical toothed cuttingmeans cutting area at the bottom of the hole within the said annular area, all the said cutting means having non-true rolling action on the formation at the bottom of the hole.

22. An earth boring drill comprising three frusto-conical toothed cutters disposed on axes inclining downwardly and inwardly towards the vertical axis of the drill, and in vertical planes intersecting said vertical axis at 120 apart, said frusto-conical cutters being of different altitudes and having toothed base portions at an angle thereto, and tracking each other to cut an annular area at the side of the bottom of the hole, the

irusto-conical cutters cutting area intermediate said annular area and the vertical axis of the drill. 23. An earth boring drill comprising two frustoconical toothed cutters the axes of which incline downwardly towards the vertical axis of the drill, said cutters being of difierent altitude and each having a toothed base portion at an angle thereto and tracking each other and cutting an area at the side of the bottom of the hole, and clearance for the drill, and a third cutter means disposed axially in a vertical plane intersecting the vertical axis of the drill 120 apart from the vertical planes intersecting said axis in which the axes of said frusto-conical cutters lie, said third cutter means cutting the entire area at the bottom of the hole and like the two frusto-conical cutters first mentioned, having non-true rolling contact with the bottom of the hole and including a frusto-conical portion of greater altitude than the said two frusto-conical cutters, the axis of said frustoconical portion inclining downwardly and inwardly in respect to the verticalaxis of the drill.

CLARENCE E. REED. 

